Part A You will create a molecular clock model for an arthropod gene. Follow these guidelines to make your
model:
• Your timeline will span from 90 million years ago to the present. The common ancestor in your model
is an arthropod that lived 90 million years ago. The gene that you'll track codes for a protein in the
species' venom.
• The DNA sequence you'll track contains 10 nitrogen bases. You can choose the order of the bases and
where the mutations occur.
This gene mutates at a rate of approximately 0.76 base pairs every 17.1 million years. To build your
model, calculate the estimated time period it takes for 1 base pair to mutate.
The first time period will only show the common ancestor. At the beginning of the second time
period, three lineages will diverge from the common ancestor, each with a different mutation in their
gene sequences.
• The first and third descendant species will survive for the rest of the timeline. The second descendant
species was extinct 50 million years ago.
Calculate how long it will take for one full base pair mutation to occur. Explain your reasoning by
constructing a mathematical equation.